Congestion and non-congestion areas: identify and measure congestion in DEA

Detecting the weak and strong congestion statuses of decision-making units (DMUs) measuring them via data envelopment analysis (DEA) is an important issue that has been discussed in several studies with different views. The efficiency frontier a concept derived from underlying production possibility set (PPS), related to them. Still, researchers have defined for each DMU many previous ignored linked technology. In measurement matter, this paper presents two new insights into area non-congestion technology mathematical definitions based on PPS properties detecting status DMUs (CSOD). We prove our are equal original definition congestion. First, we describe areas PPS; then provide full details how measure built these insights. Our approaches very accurate fast calculate; they theoretically elementary efficient performance. proposed methods can deal both non-negative negative data. Finally, empirical example provided illustrate approaches.